A noise reduction scheme for OFDM NB-PLC systems

This paper presents a low-complexity noise reduction scheme for orthogonal frequency-division multiplexing (OFDM)-based power line communication (PLC) systems. The solution exploits the positive time-correlation between the subcarrier noise magnitudes and phases. More specifically, we performed field measurements of PLC noise conducted in seven diverse locations, with continuous measurements for two days, covering the 42 kHz to 471 kHz frequency band. After analyzing the data, we have identified a key PLC noise characteristic; the subcarrier noise magnitudes are highly time-correlated in narrow frequency bands. The same behavior has also been noticed for the subcarrier noise phases. This correlation characteristic has been used to propose a simple and efficient noise reduction scheme for NB-PLC systems. We have applied the proposed method in a real case scenario, where PLC noise field measurements have been used to confirm the advantages in terms of noise reduction gain and bit error rate (BER). Indeed, depending on the channel and used modulation, the proposed scheme is able to reduce the BER by around 35 %, in the considered PLC scenarios.